When a cpu enters S3 state, the FPU state is lost.
After resuming for S3, if we try to lazy restore the FPU for a process running
on the same CPU, this will result in a corrupted FPU context.
Ensure that "fpu_owner_task" is properly invalided when (re-)initializing a CPU,
so nobody will try to lazy restore a state which doesn't exist in the hardware.
Tested with a 64-bit kernel on a 4-core Ivybridge CPU with eagerfpu=off,
by doing thousands of suspend/resume cycles with 4 processes doing FPU
operations running. Without the patch, a process is killed after a
few hundreds cycles by a SIGFPE.
Cc: Duncan Laurie <dlaurie@chromium.org>
Cc: Olof Johansson <olofj@chromium.org>
Cc: <stable@kernel.org> v3.4+ # for 3.4 need to replace this_cpu_write by percpu_write
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Link: http://lkml.kernel.org/r/1354306532-1014-1-git-send-email-vpalatin@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported
Basic design is to emulate the MSR by allowing reads and writes to a guest
vcpu specific location to store the value of the emulated MSR while adding
the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will
be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This
is of course as long as the "use TSC counter offsetting" VM-execution control
is enabled as well as the IA32_TSC_ADJUST control.
However, because hardware will only return the TSC + IA32_TSC_ADJUST +
vmsc tsc_offset for a guest process when it does and rdtsc (with the correct
settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one
of these three locations. The argument against storing it in the actual MSR
is performance. This is likely to be seldom used while the save/restore is
required on every transition. IA32_TSC_ADJUST was created as a way to solve
some issues with writing TSC itself so that is not an option either.
The remaining option, defined above as our solution has the problem of
returning incorrect vmcs tsc_offset values (unless we intercept and fix, not
done here) as mentioned above. However, more problematic is that storing the
data in vmcs tsc_offset will have a different semantic effect on the system
than does using the actual MSR. This is illustrated in the following example:
The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest
process performs a rdtsc. In this case the guest process will get
TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including
IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics
as seen by the guest do not and hence this will not cause a problem.
Signed-off-by: Will Auld <will.auld@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In order to track who initiated the call (host or guest) to modify an msr
value I have changed function call parameters along the call path. The
specific change is to add a struct pointer parameter that points to (index,
data, caller) information rather than having this information passed as
individual parameters.
The initial use for this capability is for updating the IA32_TSC_ADJUST msr
while setting the tsc value. It is anticipated that this capability is
useful for other tasks.
Signed-off-by: Will Auld <will.auld@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Create a new subsystem that probes on kernel boundaries
to keep track of the transitions between level contexts
with two basic initial contexts: user or kernel.
This is an abstraction of some RCU code that use such tracking
to implement its userspace extended quiescent state.
We need to pull this up from RCU into this new level of indirection
because this tracking is also going to be used to implement an "on
demand" generic virtual cputime accounting. A necessary step to
shutdown the tick while still accounting the cputime.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
[ paulmck: fix whitespace error and email address. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
vmcs->cpu indicates whether it exists on the target cpu, -1 means the vmcs
does not exist on any vcpu
If vcpu load vmcs with vmcs.cpu = -1, it can be directly added to cpu's percpu
list. The list can be corrupted if the cpu prefetch the vmcs's list before
reading vmcs->cpu. Meanwhile, we should remove vmcs from the list before
making vmcs->vcpu == -1 be visible
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Per Alan Cox, Nx586 did not support WP in supervisor mode, making it a
386 by Linux kernel standards. As such, it is too unsupported now.
Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Link: http://lkml.kernel.org/r/20121128205203.05868eab@pyramind.ukuu.org.uk
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Simplify the implementation of sync_core() for the case where we may
not have the CPUID instruction available.
[ v2: stylistic cleanup of the #else clause per suggestion by Borislav
Petkov. ]
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1354132230-21854-9-git-send-email-hpa@linux.intel.com
Cc: Borislav Petkov <bp@alien8.de>
* acpi-general: (38 commits)
ACPI / thermal: _TMP and _CRT/_HOT/_PSV/_ACx dependency fix
ACPI: drop unnecessary local variable from acpi_system_write_wakeup_device()
ACPI: Fix logging when no pci_irq is allocated
ACPI: Update Dock hotplug error messages
ACPI: Update Container hotplug error messages
ACPI: Update Memory hotplug error messages
ACPI: Update CPU hotplug error messages
ACPI: Add acpi_handle_<level>() interfaces
ACPI: remove use of __devexit
ACPI / PM: Add Sony Vaio VPCEB1S1E to nonvs blacklist.
ACPI / battery: Correct battery capacity values on Thinkpads
Revert "ACPI / x86: Add quirk for "CheckPoint P-20-00" to not use bridge _CRS_ info"
ACPI: create _SUN sysfs file
ACPI / memhotplug: bind the memory device when the driver is being loaded
ACPI / memhotplug: don't allow to eject the memory device if it is being used
ACPI / memhotplug: free memory device if acpi_memory_enable_device() failed
ACPI / memhotplug: fix memory leak when memory device is unbound from acpi_memhotplug
ACPI / memhotplug: deal with eject request in hotplug queue
ACPI / memory-hotplug: add memory offline code to acpi_memory_device_remove()
ACPI / memory-hotplug: call acpi_bus_trim() to remove memory device
...
Conflicts:
include/linux/acpi.h (two additions at the end of the same file)
We use XENMEM_add_to_physmap_range which is the preferred interface
for foreign mappings.
Acked-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
For Xen on ARM a PFN is 64 bits so we need to use the appropriate
type here.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: include the necessary header,
Reported-by: Fengguang Wu <fengguang.wu@intel.com> ]
The ARM platform has no concept of PVMMU and therefor no
HYPERVISOR_update_va_mapping et al. Allow this code to be compiled out
when not required.
In some similar situations (e.g. P2M) we have defined dummy functions
to avoid this, however I think we can/should draw the line at dummying
out actual hypercalls.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Also introduce xen_unmap_domain_mfn_range. These are the parts of
Mukesh's "xen/pvh: Implement MMU changes for PVH" which are also
needed as a baseline for ARM privcmd support.
The original patch was:
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This derivative is also:
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
In loaded_vmcs_clear, loaded_vmcs->cpu is the fist parameter passed to
smp_call_function_single, if the target cpu is downing (doing cpu hot remove),
loaded_vmcs->cpu can become -1 then -1 is passed to smp_call_function_single
It can be triggered when vcpu is being destroyed, loaded_vmcs_clear is called
in the preemptionable context
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
As Frederic pointed idle_cpu() may return false even if async fault
happened in the idle task if wake up is pending. In this case the code
will try to put idle task to sleep. Fix this by using is_idle_task() to
check for idle task.
Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
As on ia64 builds we get:
include/xen/interface/version.h: In function 'xen_running_on_version_or_later':
include/xen/interface/version.h:76: error: implicit declaration of function 'HYPERVISOR_xen_version'
We can later on make this function exportable if there are
modules using part of it. For right now the only two users are
built-in.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
As requested by Glauber, do not update kvmclock area on vcpu->pcpu
migration, in case the host has stable TSC.
This is to reduce cacheline bouncing.
Acked-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
With master clock, a pvclock clock read calculates:
ret = system_timestamp + [ (rdtsc + tsc_offset) - tsc_timestamp ]
Where 'rdtsc' is the host TSC.
system_timestamp and tsc_timestamp are unique, one tuple
per VM: the "master clock".
Given a host with synchronized TSCs, its obvious that
guest TSC must be matched for the above to guarantee monotonicity.
Allow master clock usage only if guest TSCs are synchronized.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM added a global variable to guarantee monotonicity in the guest.
One of the reasons for that is that the time between
1. ktime_get_ts(×pec);
2. rdtscll(tsc);
Is variable. That is, given a host with stable TSC, suppose that
two VCPUs read the same time via ktime_get_ts() above.
The time required to execute 2. is not the same on those two instances
executing in different VCPUS (cache misses, interrupts...).
If the TSC value that is used by the host to interpolate when
calculating the monotonic time is the same value used to calculate
the tsc_timestamp value stored in the pvclock data structure, and
a single <system_timestamp, tsc_timestamp> tuple is visible to all
vcpus simultaneously, this problem disappears. See comment on top
of pvclock_update_vm_gtod_copy for details.
Monotonicity is then guaranteed by synchronicity of the host TSCs
and guest TSCs.
Set TSC stable pvclock flag in that case, allowing the guest to read
clock from userspace.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Register a notifier for clocksource change event. In case
the host switches to clock other than TSC, disable master
clock usage.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Improve performance of time system calls when using Linux pvclock,
by reading time info from fixmap visible copy of pvclock data.
Originally from Jeremy Fitzhardinge.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Hook into generic pvclock vsyscall code, with the aim to
allow userspace to have visibility into pvclock data.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Originally from Jeremy Fitzhardinge.
Introduce generic, non hypervisor specific, pvclock initialization
routines.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Originally from Jeremy Fitzhardinge.
So code can be reused.
Acked-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Originally from Jeremy Fitzhardinge.
We can copy the information directly from "struct pvclock_vcpu_time_info",
remove pvclock_shadow_time.
Reviewed-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Originally from Jeremy Fitzhardinge.
pvclock_get_time_values, which contains the memory barriers
will be removed by next patch.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We want to expose the pvclock shared memory areas, which
the hypervisor periodically updates, to userspace.
For a linear mapping from userspace, it is necessary that
entire page sized regions are used for array of pvclock
structures.
There is no such guarantee with per cpu areas, therefore move
to memblock_alloc based allocation.
Acked-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Otherwise its possible for an unrelated KVM_REQ_UPDATE_CLOCK (such as due to CPU
migration) to clear the bit.
Noticed by Paolo Bonzini.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
There appear to have been some 486 clones, including the "enhanced"
version of Am486, which have CPUID but not CR4. These 486 clones had
only the FPU flag, if any, unlike the Intel 486s with CPUID, which
also had VME and therefore needed CR4.
Therefore, look at the basic CPUID flags and require at least one bit
other than bit 0 before we modify CR4.
Thanks to Christian Ludloff of sandpile.org for confirming this as a
problem.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
In __emulate_1op_rax_rdx, we use "+a" and "+d" which are input/output
constraints, and *then* use "a" and "d" as input constraints. This is
incorrect, but happens to work on some versions of gcc.
However, it breaks gcc with -O0 and icc, and may break on future
versions of gcc.
Reported-and-tested-by: Melanie Blower <melanie.blower@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/B3584E72CFEBED439A3ECA9BCE67A4EF1B17AF90@FMSMSX107.amr.corp.intel.com
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Issues that need to be handled:
* Handle PIC interrupts on any CPU irrespective of the apic mode
* In the apic lowest priority logical flat delivery mode, be prepared to
handle the interrupt on any CPU irrespective of what the IO-APIC RTE says.
* Because of above, when the IO-APIC starts handling the legacy PIC interrupt,
use the same vector that is being used by the PIC while programming the
corresponding IO-APIC RTE.
Start with all the cpu's in the legacy PIC interrupts cfg->domain.
By the time IO-APIC starts taking over the PIC interrupts, apic driver
model is finalized. So depend on the assign_irq_vector() to update the
cfg->domain and retain the same vector that was used by PIC before.
For the logical apic flat mode, cfg->domain is updated (during the first
call to assign_irq_vector()) to contain all the possible online cpu's (0xff).
Vector used for the legacy PIC interrupt doesn't change when the IO-APIC
starts handling the interrupt. Any interrupt migration after that
doesn't change the cfg->domain or the vector used.
For other apic modes like physical mode, cfg->domain is updated
(during the first call to assign_irq_vector()) to the boot cpu (cpu-0),
with the same vector that is being used by the PIC. When that interrupt is
migrated to a different cpu, cfg->domin and the vector assigned will change
accordingly.
Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1353970176.21070.51.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
With Xen acpi pad logic added into kernel, we can now revert xen mwait related
patch df88b2d96e ("xen/enlighten: Disable
MWAIT_LEAF so that acpi-pad won't be loaded. "). The reason is, when running under
newer Xen platform, Xen pad driver would be early loaded, so native pad driver
would fail to be loaded, and hence no mwait/monitor #UD risk again.
Another point is, only Xen4.2 or later support Xen acpi pad, so we won't expose
mwait cpuid capability when running under older Xen platform.
Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Conflicts:
drivers/net/wireless/iwlwifi/pcie/tx.c
Minor iwlwifi conflict in TX queue disabling between 'net', which
removed a bogus warning, and 'net-next' which added some status
register poking code.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull x86 arch fixes from Peter Anvin:
"Here is a collection of fixes for 3.7-rc7. This is a superset of
tglx' earlier pull request."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86-64: Fix ordering of CFI directives and recent ASM_CLAC additions
x86, microcode, AMD: Add support for family 16h processors
x86-32: Export kernel_stack_pointer() for modules
x86-32: Fix invalid stack address while in softirq
x86, efi: Fix processor-specific memcpy() build error
x86: remove dummy long from EFI stub
x86, mm: Correct vmflag test for checking VM_HUGETLB
x86, amd: Disable way access filter on Piledriver CPUs
x86/mce: Do not change worker's running cpu in cmci_rediscover().
x86/ce4100: Fix PCI configuration register access for devices without interrupts
x86/ce4100: Fix reboot by forcing the reboot method to be KBD
x86/ce4100: Fix pm_poweroff
MAINTAINERS: Update email address for Robert Richter
x86, microcode_amd: Change email addresses, MAINTAINERS entry
MAINTAINERS: Change Boris' email address
EDAC: Change Boris' email address
x86, AMD: Change Boris' email address
The Run Time Average Power Limiting interface
is currently model specific, present on Sandy Bridge
and Ivy Bridge processors.
These #defines correspond to documentation in the latest
"Intel® 64 and IA-32 Architectures Software Developer Manual",
plus some typos in that document corrected.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
Now that turbostat is built in the kernel tree,
it can share MSR #defines with the kernel.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
While these got added in the right place everywhere else, entry_64.S
is the odd one where they ended up before the initial CFI directive(s).
In order to cover the full code ranges, the CFI directive must be
first, though.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/5093BA1F02000078000A600E@nat28.tlf.novell.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Add valid patch size for family 16h processors.
[ hpa: promoting to urgent/stable since it is hw enabling and trivial ]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Acked-by: Andreas Herrmann <herrmann.der.user@googlemail.com>
Link: http://lkml.kernel.org/r/1353004910-2204-1-git-send-email-boris.ostrovsky@amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
Modules, in particular oprofile (and possibly other similar tools)
need kernel_stack_pointer(), so export it using EXPORT_SYMBOL_GPL().
Cc: Yang Wei <wei.yang@windriver.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Jun Zhang <jun.zhang@intel.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20120912135059.GZ8285@erda.amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Building for Athlon/Duron/K7 results in the following build error,
arch/x86/boot/compressed/eboot.o: In function `__constant_memcpy3d':
eboot.c:(.text+0x385): undefined reference to `_mmx_memcpy'
arch/x86/boot/compressed/eboot.o: In function `efi_main':
eboot.c:(.text+0x1a22): undefined reference to `_mmx_memcpy'
because the boot stub code doesn't link with the kernel proper, and
therefore doesn't have access to the 3DNow version of memcpy. So,
follow the example of misc.c and #undef memcpy so that we use the
version provided by misc.c.
See https://bugzilla.kernel.org/show_bug.cgi?id=50391
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Ryan Underwood <nemesis@icequake.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@vger.kernel.org
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Commit 2e064b1 (x86, efi: Fix issue of overlapping .reloc section for
EFI_STUB) removed a dummy reloc added by commit 291f363 (x86, efi: EFI
boot stub support), but forgot to remove the dummy long used by that
reloc.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Tested-by: Lee G Rosenbaum <lee.g.rosenbaum@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Commit 77d1a49995 ("x86, boot: make
symbols from the main vmlinux available") removed all traces of
offsets.h from the tree. Remove its entries in dontdiff and x86/boot's
.gitignore file too.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This reverts commit 0a290ac425 on
the basis of the following comment from Bjorn Helgaas:
Here's my reasoning: this is a CheckPoint product, and it looks
like an appliance, not really a general-purpose machine. The issue
has apparently been there from day one, and the kernel shipped on
the machine complains noisily about the issue, but apparently
nobody bothered to investigate it.
This corruption will clearly break other ACPI-related things. We
can sort of work around this one (though the workaround does
prevent us from doing any PCI resource reassignment), but we have
no idea what the other lurking ACPI issues are (and we have no
assurance that *only* ACPI things are broken -- maybe the
memory corruption affects other unknown things). It may take
significant debugging effort to identify the next problem.
The only report I've seen (this one) is apparently from a
CheckPoint employee, so it's not clear that anybody else is trying
to run upstream Linux on it. Being a CheckPoint employee, [...]
is probably in a position to get the BIOS fixed.
You might still be able to convince me, but it seems like the
benefit to a quirk for this platform is small, and it does cost
everybody else something in code size and complexity.
References: https://bugzilla.kernel.org/show_bug.cgi?id=47981#c36
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CONFIG_DEBUG_HOTPLUG_CPU0 is for debugging the CPU0 hotplug feature. The switch
offlines CPU0 as soon as possible and boots userspace up with CPU0 offlined.
User can online CPU0 back after boot time. The default value of the switch is
off.
To debug CPU0 hotplug, you need to enable CPU0 offline/online feature by either
turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during compilation or giving
cpu0_hotplug kernel parameter at boot.
It's safe and early place to take down CPU0 after all hotplug notifiers
are installed and SMP is booted.
Please note that some applications or drivers, e.g. some versions of udevd,
during boot time may put CPU0 online again in this CPU0 hotplug debug mode.
In this debug mode, setup_local_APIC() may report a warning on max_loops<=0
when CPU0 is onlined back after boot time. This is because pending interrupt in
IRR can not move to ISR. The warning is not CPU0 specfic and it can happen on
other CPUs as well. It is harmless except the first CPU0 online takes a bit
longer time. And so this debug mode is useful to expose this issue. I'll send
a seperate patch to fix this generic warning issue.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-15-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The first cpu in irq cfg->domain is likely to be CPU 0 and may not be available
when CPU 0 is offline. Instead of using CPU 0 to handle retriggered irq, we use
first available CPU which is online and in this irq's domain.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-13-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Previously these functions were not run on the BSP (CPU 0, the boot processor)
since the boot processor init would only be executed before this functionality
was initialized.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-11-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Instead of waiting for STARTUP after INITs, BSP will execute the BIOS boot-strap
code which is not a desired behavior for waking up BSP. To avoid the boot-strap
code, wake up CPU0 by NMI instead.
This works to wake up soft offlined CPU0 only. If CPU0 is hard offlined (i.e.
physically hot removed and then hot added), NMI won't wake it up. We'll change
this code in the future to wake up hard offlined CPU0 if real platform and
request are available.
AP is still waken up as before by INIT, SIPI, SIPI sequence.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352896613-25957-1-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
These functions might be called from modules as well so make sure
they are exported.
In addition, implement empty version of acpi_unregister_gsi() and
remove the one from pci_irq.c.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
With ACPI 5 we are starting to see devices that don't natively support
discovery but can be enumerated with the help of the ACPI namespace.
Typically, these devices can be represented in the Linux device driver
model as platform devices or some serial bus devices, like SPI or I2C
devices.
Since we want to re-use existing drivers for those devices, we need a
way for drivers to specify the ACPI IDs of supported devices, so that
they can be matched against device nodes in the ACPI namespace. To
this end, it is sufficient to add a pointer to an array of supported
ACPI device IDs, that can be provided by the driver, to struct device.
Moreover, things like ACPI power management need to have access to
the ACPI handle of each supported device, because that handle is used
to invoke AML methods associated with the corresponding ACPI device
node. The ACPI handles of devices are now stored in the archdata
member structure of struct device whose definition depends on the
architecture and includes the ACPI handle only on x86 and ia64. Since
the pointer to an array of supported ACPI IDs is added to struct
device_driver in an architecture-independent way, it is logical to
move the ACPI handle from archdata to struct device itself at the same
time. This also makes code more straightforward in some places and
follows the example of Device Trees that have a poiter to struct
device_node in there too.
This changeset is based on Mika Westerberg's work.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The ACPI specificiation would like us to save NVS at hibernation time,
but makes no mention of saving NVS over S3. Not all versions of
Windows do this either, and it is clear that not all machines need NVS
saved/restored over S3. Allow the user to improve their suspend/resume
time by disabling the NVS save/restore at S3 time, but continue to do
the NVS save/restore for S4 as specified.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This is to fix a regression https://bugzilla.kernel.org/show_bug.cgi?id=47981
The CheckPoint P-20-00 works ok before new machines (2008 and later) are
forced to use the bridge _CRS info by default in 2.6.34. Add this quirk
to restore its old way of working: not using bridge _CRS info.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
commit 611ae8e3f5204f7480b3b405993b3352cfa16662('enable tlb flush range
support for x86') change flush_tlb_mm_range() considerably. After this,
we test whether vmflag equal to VM_HUGETLB and it may be always failed,
because vmflag usually has other flags simultaneously.
Our intention is to check whether this vma is for hughtlb, so correct it
according to this purpose.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Acked-by: Alex Shi <alex.shi@intel.com>
Link: http://lkml.kernel.org/r/1352740656-19417-1-git-send-email-js1304@gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Because x86 BIOS requires CPU0 to resume from sleep, suspend or hibernate can't
be executed if CPU0 is detected offline. To make suspend or hibernate and
further resume succeed, CPU0 must be online.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-6-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Add smp_store_boot_cpu_info() to store cpu info for BSP during boot time.
Now smp_store_cpu_info() stores cpu info for bringing up BSP or AP after
it's offline.
Continue to online CPU0 in native_cpu_up().
Continue to offline CPU0 in native_cpu_disable().
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-5-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
If CONFIG_BOOTPARAM_HOTPLUG_CPU is turned on, CPU0 hotplug feature is enabled
by default.
If CONFIG_BOOTPARAM_HOTPLUG_CPU is not turned on, CPU0 hotplug feature is not
enabled by default. The kernel parameter cpu0_hotplug can enable CPU0 hotplug
feature at boot.
Currently the feature is supported on Intel platforms only.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-4-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
New config switch CONFIG_BOOTPARAM_HOTPLUG_CPU0 sets default state of whether
the CPU0 hotplug is on or off.
If the switch is off, CPU0 is not hotpluggable by default. But the CPU0 hotplug
feature can still be turned on by kernel parameter cpu0_hotplug at boot.
If the switch is on, CPU0 is always hotpluggable.
The default value of the switch is off.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-3-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Header length should be validated for all ACPI tables before accessing
any non-header field.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/509A9E6002000078000A7079@nat28.tlf.novell.com
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
No need to check return value before breaking switch.
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Return value of this function will be that of ioctl().
#include <stdio.h>
#include <linux/kvm.h>
int main () {
int fd;
fd = open ("/dev/kvm", 0);
fd = ioctl (fd, KVM_CREATE_VM, 0);
ioctl (fd, KVM_SET_TSS_ADDR, 0xfffff000);
perror ("");
return 0;
}
Output is "Operation not permitted". That's not what
we want.
Return -EINVAL in this case.
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We should avoid kfree()ing error pointer in kvm_vcpu_ioctl() and
kvm_arch_vcpu_ioctl().
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In order to promote interoperability between userspace tracers and ftrace,
add a trace_clock that reports raw TSC values which will then be recorded
in the ring buffer. Userspace tracers that also record TSCs are then on
exactly the same time base as the kernel and events can be unambiguously
interlaced.
Tested: Enabled a tracepoint and the "tsc" trace_clock and saw very large
timestamp values.
v2:
Move arch-specific bits out of generic code.
v3:
Rename "x86-tsc", cleanups
v7:
Generic arch bits in Kbuild.
Google-Bug-Id: 6980623
Link: http://lkml.kernel.org/r/1352837903-32191-1-git-send-email-dhsharp@google.com
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Signed-off-by: David Sharp <dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The patch is based on a patch submitted by Hans Rosenfeld.
See http://marc.info/?l=linux-kernel&m=133908777200931
Note that CPUID Fn8000_001D_EAX slightly differs to Intel's CPUID function 4.
Bits 14-25 contain NumSharingCache. Actual number of cores sharing
this cache. SW to add value of one to get result.
The corresponding bits on Intel are defined as "maximum number of threads
sharing this cache" (with a "plus 1" encoding).
Thus a different method to determine which cores are sharing a cache
level has to be used.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Link: http://lkml.kernel.org/r/20121019090209.GG26718@alberich
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Rely on CPUID 0x8000001d for cache information when AMD CPUID topology
extensions are available.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Link: http://lkml.kernel.org/r/20121019090049.GF26718@alberich
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
CPUID 0x8000001d works quite similar to Intels' CPUID function 4.
Use it to determine number of cache leafs.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Link: http://lkml.kernel.org/r/20121019085933.GE26718@alberich
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Introduce cpu_has_topoext to check for AMD's CPUID topology extensions
support. It indicates support for
CPUID Fn8000_001D_EAX_x[N:0]-CPUID Fn8000_001E_EDX
See AMD's CPUID Specification, Publication # 25481
(as of Rev. 2.34 September 2010)
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Link: http://lkml.kernel.org/r/20121019085813.GD26718@alberich
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
migrating worker threads to other cpus.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=tv13
-----END PGP SIGNATURE-----
Merge tag 'please-pull-tangchen' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/urgent
Pull MCE fix from Tony Luck:
"Fix problem in CMCI rediscovery code that was illegally
migrating worker threads to other cpus."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull KVM fix from Marcelo Tosatti:
"A correction for user triggerable oops"
* git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: invalid opcode oops on SET_SREGS with OSXSAVE bit set (CVE-2012-4461)
On hosts without the XSAVE support unprivileged local user can trigger
oops similar to the one below by setting X86_CR4_OSXSAVE bit in guest
cr4 register using KVM_SET_SREGS ioctl and later issuing KVM_RUN
ioctl.
invalid opcode: 0000 [#2] SMP
Modules linked in: tun ip6table_filter ip6_tables ebtable_nat ebtables
...
Pid: 24935, comm: zoog_kvm_monito Tainted: G D 3.2.0-3-686-pae
EIP: 0060:[<f8b9550c>] EFLAGS: 00210246 CPU: 0
EIP is at kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm]
EAX: 00000001 EBX: 000f387e ECX: 00000000 EDX: 00000000
ESI: 00000000 EDI: 00000000 EBP: ef5a0060 ESP: d7c63e70
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process zoog_kvm_monito (pid: 24935, ti=d7c62000 task=ed84a0c0
task.ti=d7c62000)
Stack:
00000001 f70a1200 f8b940a9 ef5a0060 00000000 00200202 f8769009 00000000
ef5a0060 000f387e eda5c020 8722f9c8 00015bae 00000000 ed84a0c0 ed84a0c0
c12bf02d 0000ae80 ef7f8740 fffffffb f359b740 ef5a0060 f8b85dc1 0000ae80
Call Trace:
[<f8b940a9>] ? kvm_arch_vcpu_ioctl_set_sregs+0x2fe/0x308 [kvm]
...
[<c12bfb44>] ? syscall_call+0x7/0xb
Code: 89 e8 e8 14 ee ff ff ba 00 00 04 00 89 e8 e8 98 48 ff ff 85 c0 74
1e 83 7d 48 00 75 18 8b 85 08 07 00 00 31 c9 8b 95 0c 07 00 00 <0f> 01
d1 c7 45 48 01 00 00 00 c7 45 1c 01 00 00 00 0f ae f0 89
EIP: [<f8b9550c>] kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm] SS:ESP
0068:d7c63e70
QEMU first retrieves the supported features via KVM_GET_SUPPORTED_CPUID
and then sets them later. So guest's X86_FEATURE_XSAVE should be masked
out on hosts without X86_FEATURE_XSAVE, making kvm_set_cr4 with
X86_CR4_OSXSAVE fail. Userspaces that allow specifying guest cpuid with
X86_FEATURE_XSAVE even on hosts that do not support it, might be
susceptible to this attack from inside the guest as well.
Allow setting X86_CR4_OSXSAVE bit only if host has XSAVE support.
Signed-off-by: Petr Matousek <pmatouse@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Conflicts:
drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
Minor conflict between the BCM_CNIC define removal in net-next
and a bug fix added to net. Based upon a conflict resolution
patch posted by Stephen Rothwell.
Signed-off-by: David S. Miller <davem@davemloft.net>
* Fix compile issues on ARM.
* Fix hypercall fallback code for old hypervisors.
* Print out which HVM parameter failed if it fails.
* Fix idle notifier call after irq_enter.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
iQEcBAABAgAGBQJQnQdGAAoJEFjIrFwIi8fJPBAIAMX1HRx3udqhv7fziynZvFTb
hj47XYIJHOK7P4fK7vZoSNgMHjL6LW5cUqC8VN67G3zUSkX9JYFsPBj6v4bWn+rG
b9CS+MW7hS80LGbbqkh1F+YSEfZ863RlF9PPX2acaHTw49MlIgIqwhxIo6hy+Nm6
thu6SlbEIJkSUdhbYMOAmy5aH/3+UuuQg+oq3P7mzV8fZjEihnrrF0NlT4wOZK1o
gsfrKYKJLVT526W9PF/L23/A/MCHMpvjNStpaDLOGNjV9sBMpJI8JRax6+657+q1
0kXvN5mAwTKWOaXBl4LEC9R8n1IKB91TgOY6HJAcXkb1eoP5KAeNSmU8RbsZ2T0=
=XZ+0
-----END PGP SIGNATURE-----
Merge tag 'stable/for-linus-3.7-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen fixes from Konrad Rzeszutek Wilk:
"There are three ARM compile fixes (we forgot to export certain
functions and if the drivers are built as an module - we go belly-up).
There is also an mismatch of irq_enter() / exit_idle() calls sequence
which were fixed some time ago in other piece of codes, but failed to
appear in the Xen code.
Lastly a fix for to help in the field with troubleshooting in case we
cannot get the appropriate parameter and also fallback code when
working with very old hypervisors."
Bug-fixes:
- Fix compile issues on ARM.
- Fix hypercall fallback code for old hypervisors.
- Print out which HVM parameter failed if it fails.
- Fix idle notifier call after irq_enter.
* tag 'stable/for-linus-3.7-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/arm: Fix compile errors when drivers are compiled as modules (export more).
xen/arm: Fix compile errors when drivers are compiled as modules.
xen/generic: Disable fallback build on ARM.
xen/events: fix RCU warning, or Call idle notifier after irq_enter()
xen/hvm: If we fail to fetch an HVM parameter print out which flag it is.
xen/hypercall: fix hypercall fallback code for very old hypervisors
* pci/taku-prt-cleanup:
PCI/ACPI: Request _OSC control before scanning PCI root bus
PCI: Don't pass pci_dev to pci_ext_cfg_avail()
PCI/ACPI: Add _PRT interrupt routing info before enumerating devices
ACPI: Pass segment/bus to _PRT add/del so they don't depend on pci_bus
Prepare camellia-x86_64 functions to be reused from AVX/AESNI implementation
module.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Export asm/{svm.h,vmx.h,perf_regs.h} so that they can be disintegrated.
It looks from previous commits that the first two should have been exported,
but the header-y lines weren't added to the Kbuild.
I'm guessing that asm/perf_regs.h should be exported too.
Signed-off-by: David Howells <dhowells@redhat.com>
The memory range descriptors in the _CRS control method contain an address
translation offset for host bridges. This value is used to translate
addresses across the bridge. The support to use _TRA values is present for
other architectures but not for X86 platforms.
For existing X86 platforms the _TRA value is zero. Non-zero _TRA values
are expected on future X86 platforms. This change will register that value
with the resource.
Signed-off-by: Mike Yoknis <mike.yoknis@hp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The xw9300 BIOS supplies _SEG methods that are incorrect, which results
in some LSI SCSI devices not being discovered. This adds a quirk to
ignore _SEG on this machine and default to zero.
The xw9300 has three host bridges:
ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-3f])
ACPI: PCI Root Bridge [PCI1] (domain 0001 [bus 40-7f])
ACPI: PCI Root Bridge [PCI2] (domain 0002 [bus 80-ff])
When the BIOS "ACPI Bus Segmentation" option is enabled (as it is by
default), the _SEG methods of the PCI1 and PCI2 bridges return 1 and 2,
respectively. However, the BIOS implementation appears to be incomplete,
and we can't enumerate devices in those domains.
But if we assume PCI1 and PCI2 really lead to buses in domain 0,
everything works fine. Windows XP and Vista also seem to ignore
these _SEG methods.
Reference: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=543308
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=15362
Reported-and-Tested-by: Sean M. Pappalardo <pegasus@renegadetech.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
pci_ext_cfg_avail() doesn't use the "struct pci_dev *" passed to
it, and there's no requirement that a host bridge even be represented
by a pci_dev. This drops the pci_ext_cfg_avail() parameter.
[bhelgaas: changelog]
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
While copying the argument structures in HYPERVISOR_event_channel_op()
and HYPERVISOR_physdev_op() into the local variable is sufficiently
safe even if the actual structure is smaller than the container one,
copying back eventual output values the same way isn't: This may
collide with on-stack variables (particularly "rc") which may change
between the first and second memcpy() (i.e. the second memcpy() could
discard that change).
Move the fallback code into out-of-line functions, and handle all of
the operations known by this old a hypervisor individually: Some don't
require copying back anything at all, and for the rest use the
individual argument structures' sizes rather than the container's.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
[v2: Reduce #define/#undef usage in HYPERVISOR_physdev_op_compat().]
[v3: Fix compile errors when modules use said hypercalls]
[v4: Add xen_ prefix to the HYPERCALL_..]
[v5: Alter the name and only EXPORT_SYMBOL_GPL one of them]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
No functional changes.
Now that default arch_uprobe_enable/disable_step() helpers do nothing,
x86 has no reason to reimplement them. Change arch_uprobe_*_xol() hooks
to do the necessary work and remove the x86-specific hooks.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
setup_hpet_msi_remapped() returns a negative error indicator on error
- check for this rather than for a boolean false indication, and pass
on that error code rather than a meaningless "-1".
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Link: http://lkml.kernel.org/r/5093E00D02000078000A60E2@nat28.tlf.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
HPET_TN_FSB is not a proper mask bit; it merely toggles between MSI and
legacy interrupt delivery. The proper mask bit is HPET_TN_ENABLE, so
use both bits when (un)masking the interrupt.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/5093E09002000078000A60E6@nat28.tlf.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The nested NMI modifies the place (instruction, flags and stack)
that the first NMI will iret to. However, the copy of registers
modified is exactly the one that is the part of pt_regs in
the first NMI. This can change the behaviour of the first NMI.
In particular, Google's arch_trigger_all_cpu_backtrace handler
also prints regions of memory surrounding addresses appearing in
registers. This results in handled exceptions, after which nested NMIs
start coming in. These nested NMIs change the value of registers
in pt_regs. This can cause the original NMI handler to produce
incorrect output.
We solve this problem by interchanging the position of the preserved
copy of the iret registers ("saved") and the copy subject to being
trampled by nested NMI ("copied").
Link: http://lkml.kernel.org/r/20121002002919.27236.14388.stgit@dungbeetle.mtv.corp.google.com
Signed-off-by: Salman Qazi <sqazi@google.com>
[ Added a needed CFI_ADJUST_CFA_OFFSET ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This is a respin of 00e37bdb01
("xen PVonHVM: move shared_info to MMIO before kexec").
Currently kexec in a PVonHVM guest fails with a triple fault because the
new kernel overwrites the shared info page. The exact failure depends on
the size of the kernel image. This patch moves the pfn from RAM into an
E820 reserved memory area.
The pfn containing the shared_info is located somewhere in RAM. This will
cause trouble if the current kernel is doing a kexec boot into a new
kernel. The new kernel (and its startup code) can not know where the pfn
is, so it can not reserve the page. The hypervisor will continue to update
the pfn, and as a result memory corruption occours in the new kernel.
The toolstack marks the memory area FC000000-FFFFFFFF as reserved in the
E820 map. Within that range newer toolstacks (4.3+) will keep 1MB
starting from FE700000 as reserved for guest use. Older Xen4 toolstacks
will usually not allocate areas up to FE700000, so FE700000 is expected
to work also with older toolstacks.
In Xen3 there is no reserved area at a fixed location. If the guest is
started on such old hosts the shared_info page will be placed in RAM. As
a result kexec can not be used.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If the TSC deadline mode is supported, LAPIC timer one-shot mode can be
implemented using IA32_TSC_DEADLINE MSR. An interrupt will be generated
when the TSC value equals or exceeds the value in the IA32_TSC_DEADLINE
MSR.
This enables us to skip the APIC calibration during boot. Also, in
xapic mode, this enables us to skip the uncached apic access to re-arm
the APIC timer.
As this timer ticks at the high frequency TSC rate, we use the
TSC_DIVISOR (32) to work with the 32-bit restrictions in the
clockevent API's to avoid 64-bit divides etc (frequency is u32 and
"unsigned long" in the set_next_event(), max_delta limits the next
event to 32-bit for 32-bit kernel).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: venki@google.com
Cc: len.brown@intel.com
Link: http://lkml.kernel.org/r/1350941878.6017.31.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
After commit b3356bf0db (KVM: emulator: optimize "rep ins" handling),
the pieces of io data can be collected and write them to the guest memory
or MMIO together
Unfortunately, kvm splits the mmio access into 8 bytes and store them to
vcpu->mmio_fragments. If the guest uses "rep ins" to move large data, it
will cause vcpu->mmio_fragments overflow
The bug can be exposed by isapc (-M isapc):
[23154.818733] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[ ......]
[23154.858083] Call Trace:
[23154.859874] [<ffffffffa04f0e17>] kvm_get_cr8+0x1d/0x28 [kvm]
[23154.861677] [<ffffffffa04fa6d4>] kvm_arch_vcpu_ioctl_run+0xcda/0xe45 [kvm]
[23154.863604] [<ffffffffa04f5a1a>] ? kvm_arch_vcpu_load+0x17b/0x180 [kvm]
Actually, we can use one mmio_fragment to store a large mmio access then
split it when we pass the mmio-exit-info to userspace. After that, we only
need two entries to store mmio info for the cross-mmio pages access
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The Way Access Filter in recent AMD CPUs may hurt the performance of
some workloads, caused by aliasing issues in the L1 cache.
This patch disables it on the affected CPUs.
The issue is similar to that one of last year:
http://lkml.indiana.edu/hypermail/linux/kernel/1107.3/00041.html
This new patch does not replace the old one, we just need another
quirk for newer CPUs.
The performance penalty without the patch depends on the
circumstances, but is a bit less than the last year's 3%.
The workloads affected would be those that access code from the same
physical page under different virtual addresses, so different
processes using the same libraries with ASLR or multiple instances of
PIE-binaries. The code needs to be accessed simultaneously from both
cores of the same compute unit.
More details can be found here:
http://developer.amd.com/Assets/SharedL1InstructionCacheonAMD15hCPU.pdf
CPUs affected are anything with the core known as Piledriver.
That includes the new parts of the AMD A-Series (aka Trinity) and the
just released new CPUs of the FX-Series (aka Vishera).
The model numbering is a bit odd here: FX CPUs have model 2,
A-Series has model 10h, with possible extensions to 1Fh. Hence the
range of model ids.
Signed-off-by: Andre Przywara <osp@andrep.de>
Link: http://lkml.kernel.org/r/1351700450-9277-1-git-send-email-osp@andrep.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch is a follow-up for patch "net: filter: add vlan tag access"
to support the new VLAN_TAG/VLAN_TAG_PRESENT accessors in BPF JIT.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ani Sinha <ani@aristanetworks.com>
Cc: Daniel Borkmann <danborkmann@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
As Mukesh explained it, the MMUEXT_TLB_FLUSH_ALL allows the
hypervisor to do a TLB flush on all active vCPUs. If instead
we were using the generic one (which ends up being xen_flush_tlb)
we end up making the MMUEXT_TLB_FLUSH_LOCAL hypercall. But
before we make that hypercall the kernel will IPI all of the
vCPUs (even those that were asleep from the hypervisor
perspective). The end result is that we needlessly wake them
up and do a TLB flush when we can just let the hypervisor
do it correctly.
This patch gives around 50% speed improvement when migrating
idle guest's from one host to another.
Oracle-bug: 14630170
CC: stable@vger.kernel.org
Tested-by: Jingjie Jiang <jingjie.jiang@oracle.com>
Suggested-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Other than ix86, x86-64 on EFI so far didn't set the
{g,s}et_wallclock accessors to the EFI routines, thus
incorrectly using raw RTC accesses instead.
Simply removing the #ifdef around the respective code isn't
enough, however: While so far early get-time calls were done in
physical mode, this doesn't work properly for x86-64, as virtual
addresses would still need to be set up for all runtime regions
(which wasn't the case on the system I have access to), so
instead the patch moves the call to efi_enter_virtual_mode()
ahead (which in turn allows to drop all code related to calling
efi-get-time in physical mode).
Additionally the earlier calling of efi_set_executable()
requires the CPA code to cope, i.e. during early boot it must be
avoided to call cpa_flush_array(), as the first thing this
function does is a BUG_ON(irqs_disabled()).
Also make the two EFI functions in question here static -
they're not being referenced elsewhere.
History:
This commit was originally merged as bacef661ac ("x86-64/efi:
Use EFI to deal with platform wall clock") but it resulted in some
ASUS machines no longer booting due to a firmware bug, and so was
reverted in f026cfa82f. A pre-emptive fix for the buggy ASUS
firmware was merged in 03a1c254975e ("x86, efi: 1:1 pagetable
mapping for virtual EFI calls") so now this patch can be
reapplied.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Matt Fleming <matt.fleming@intel.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com> [added commit history]
For TXT boot, while Linux kernel trys to shutdown/S3/S4/reboot, it
need to jump back to tboot code and do TXT teardown work. Previously
kernel zapped all mem page identity mapping (va=pa) after booting, so
tboot code mem address was mapped again with identity mapping. Now
kernel didn't zap the identity mapping page table, so tboot related
code can remove the remapping code before trapping back now.
Signed-off-by: Xiaoyan Zhang <xiaoyan.zhang@intel.com>
Acked-by: Gang Wei <gang.wei@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Some firmware still needs a 1:1 (virt->phys) mapping even after we've
called SetVirtualAddressMap(). So install the mapping alongside our
existing kernel mapping whenever we make EFI calls in virtual mode.
This bug was discovered on ASUS machines where the firmware
implementation of GetTime() accesses the RTC device via physical
addresses, even though that's bogus per the UEFI spec since we've
informed the firmware via SetVirtualAddressMap() that the boottime
memory map is no longer valid.
This bug seems to be present in a lot of consumer devices, so there's
not a lot we can do about this spec violation apart from workaround
it.
Cc: JérômeCarretero <cJ-ko@zougloub.eu>
Cc: Vasco Dias <rafa.vasco@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
There are various pieces of code in arch/x86 that require a page table
with an identity mapping. Make trampoline_pgd a proper kernel page
table, it currently only includes the kernel text and module space
mapping.
One new feature of trampoline_pgd is that it now has mappings for the
physical I/O device addresses, which are inserted at ioremap()
time. Some broken implementations of EFI firmware require these
mappings to always be around.
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Some CE4100 devices such as the:
- DFX module (01:0b.7)
- entertainment encryption device (01:10.0)
- multimedia controller (01:12.0)
do not have a device interrupt at all.
This patch fixes the PCI controller code to declare the missing
PCI configuration register space, as well as a fixup method for
forcing the interrupt pin to be 0 for these devices. This is
required to ensure that pci drivers matching on these devices
will be able to honor the various PCI subsystem calls touching
the configuration space.
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: rui.zhang@intel.com
Cc: alan@linux.intel.com
Link: http://lkml.kernel.org/r/1351518020-25556-4-git-send-email-ffainelli@freebox.fr
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The default reboot is via ACPI for this platform, and the CEFDK
bootloader actually supports this, but will issue a system power
off instead of a real reboot. Setting the reboot method to be
KBD instead of ACPI ensures proper system reboot.
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
Cc: rui.zhang@intel.com
Cc: alan@linux.intel.com
Link: http://lkml.kernel.org/r/1351518020-25556-3-git-send-email-ffainelli@freebox.fr
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The CE4100 platform is currently missing a proper pm_poweroff
implementation leading to poweroff making the CPU spin forever
and the CE4100 platform does not enter a low-power mode where
the external Power Management Unit can properly power off the
system. Power off on this platform is implemented pretty much
like reboot, by writing to the SoC built-in 8051 microcontroller
mapped at I/O port 0xcf9, the value 0x4.
Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: rui.zhang@intel.com
Cc: alan@linux.intel.com
Link: http://lkml.kernel.org/r/1351518020-25556-2-git-send-email-ffainelli@freebox.fr
Signed-off-by: Ingo Molnar <mingo@kernel.org>
FYI, there are new sparse warnings:
arch/x86/kernel/cpu/perf_event.c:1356:18: sparse: symbol 'events_attr' was not declared. Should it be static?
This patch makes it static and also adds the static keyword to
fix arch/x86/kernel/cpu/perf_event.c:1344:9: warning: symbol
'events_sysfs_show' was not declared.
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: fengguang.wu@intel.com
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-lerdpXlnruh0yvWs2owwuizl@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch filters noslot pfn out from error pfns based on Marcelo comment:
noslot pfn is not a error pfn
After this patch,
- is_noslot_pfn indicates that the gfn is not in slot
- is_error_pfn indicates that the gfn is in slot but the error is occurred
when translate the gfn to pfn
- is_error_noslot_pfn indicates that the pfn either it is error pfns or it
is noslot pfn
And is_invalid_pfn can be removed, it makes the code more clean
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Merge reason: development work has dependency on kvm patches merged
upstream.
Conflicts:
arch/powerpc/include/asm/Kbuild
arch/powerpc/include/asm/kvm_para.h
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
On x86-64 syscall exit, 3 non exclusive events may happen
looping in the following order:
1) Check if we need resched for user preemption, if so call
schedule_user()
2) Check if we have pending signals, if so call do_notify_resume()
3) Check if we do syscall tracing, if so call syscall_trace_leave()
However syscall_trace_leave() has been written assuming it directly
follows the syscall and forget about the above possible 1st and 2nd
steps.
Now schedule_user() and do_notify_resume() exit in RCU user mode
because they have most chances to resume userspace immediately and
this avoids an rcu_user_enter() call in the syscall fast path.
So by the time we call syscall_trace_leave(), we may well be in RCU
user mode. To fix this up, simply call rcu_user_exit() in the beginning
of this function.
This fixes some reported RCU uses in extended quiescent state.
Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Pull x86 fixes from Ingo Molnar:
"This fixes a couple of nasty page table initialization bugs which were
causing kdump regressions. A clean rearchitecturing of the code is in
the works - meanwhile these are reverts that restore the
best-known-working state of the kernel.
There's also EFI fixes and other small fixes."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, mm: Undo incorrect revert in arch/x86/mm/init.c
x86: efi: Turn off efi_enabled after setup on mixed fw/kernel
x86, mm: Find_early_table_space based on ranges that are actually being mapped
x86, mm: Use memblock memory loop instead of e820_RAM
x86, mm: Trim memory in memblock to be page aligned
x86/irq/ioapic: Check for valid irq_cfg pointer in smp_irq_move_cleanup_interrupt
x86/efi: Fix oops caused by incorrect set_memory_uc() usage
x86-64: Fix page table accounting
Revert "x86/mm: Fix the size calculation of mapping tables"
MAINTAINERS: Add EFI git repository location
them together into a mca_config struct. This keeps them tightly and
neatly packed together instead of spilled all over the place.
Then, convert those which are used as booleans into real booleans and
save some space.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=EOHq
-----END PGP SIGNATURE-----
Merge tag 'mca_cfg' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/ras
Pull x86 RAS changes from Borislav Petkov:
"Rework all config variables used throughout the MCA code and collect
them together into a mca_config struct. This keeps them tightly and
neatly packed together instead of spilled all over the place.
Then, convert those which are used as booleans into real booleans and
save some space."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
mce_ser, mce_bios_cmci_threshold and mce_disabled are the last three
bools which need conversion. Move them to the mca_config struct and
adjust usage sites accordingly.
Signed-off-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Move them into the mca_config struct and adjust code touching them
accordingly.
Signed-off-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Move those MCA configuration variables into struct mca_config and adjust
the places they're used accordingly.
Signed-off-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
The hlt_use_halt function returns always true and there is only
one definition of it.
The default_idle function can then get ride of the if ...
statement and we can remove the else branch.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linaro-dev@lists.linaro.org
Cc: patches@linaro.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1351181591-8710-1-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
MPS tables are not needed for systems that have proper ACPI
support. This is also true for systems that have SFI in place.
So this patch allows the configuration (turning off) of
CONFIG_X86_MPPARSE when either ACPI or SFI is present.
Signed-off-by: Bin Gao <bin.gao@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Bin Gao <bin.gao@linux.intel.com>
Link: http://lkml.kernel.org/r/20121025163544.GB38477@bingao-desk1.fm.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit
844ab6f9 x86, mm: Find_early_table_space based on ranges that are actually being mapped
added back some lines back wrongly that has been removed in commit
7b16bbf97 Revert "x86/mm: Fix the size calculation of mapping tables"
remove them again.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQW_vuaYQbmagVnxT2DGsYc=9tNeAbdBq53sYkitPOwxSQ@mail.gmail.com
Acked-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
When 32-bit EFI is used with 64-bit kernel (or vice versa), turn off
efi_enabled once setup is done. Beyond setup, it is normally used to
determine if runtime services are available and we will have none.
This will resolve issues stemming from efivars modprobe panicking on a
32/64-bit setup, as well as some reboot issues on similar setups.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=45991
Reported-by: Marko Kohtala <marko.kohtala@gmail.com>
Reported-by: Maxim Kammerer <mk@dee.su>
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: stable@kernel.org # 3.4 - 3.6
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Current logic finds enough space for direct mapping page tables from 0
to end. Instead, we only need to find enough space to cover mr[0].start
to mr[nr_range].end -- the range that is actually being mapped by
init_memory_mapping()
This is needed after 1bbbbe779a, to address
the panic reported here:
https://lkml.org/lkml/2012/10/20/160https://lkml.org/lkml/2012/10/21/157
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/20121024195311.GB11779@jshin-Toonie
Tested-by: Tom Rini <trini@ti.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
